1. Field of the Invention
The present invention relates to lifting devices, namely cranes. More particularly, the present invention relates to an improved knuckle boom king post crane apparatus that employs a rack and pinion mechanism to articulate one boom section relative to another boom section and a unique knuckle boom luffing arrangement.
2. General Background of the Invention
A knuckle boom crane is a hydraulically powered articulated arm that can be fitted to a support structure, usually a truck or trailer. The jointed sections of the boom can be folded into a small space when the crane is not in use.
Several articulated boom crane constructions have been patented. Examples of possibly relevant patents can be found below.
The following US patents for cranes listed in the table below are each incorporated herein by reference:
TABLEISSUEDATEPAT. NO.TITLEmm/dd/yyyy4,105,151Crane Conversion Method08/08/19784,184,600Method for Removing a Bearing Assembly of a01/22/1980Pedestal Crane and a Removable BearingAssembly for a Pedestal Crane4,216,870Crane Mounting08/12/19804,354,606Bearing Assembly for a Pedestal Crane10/19/19824,513,869Pedestal Crane Mounting System04/30/19854,602,462Boom Articulating Mechanism for Aerial07/29/1986Devices4,688,688Jib Crane Arrangement Having a Rotatable08/25/1987Mast4,828,125Device for Maintaining a Tool Attachment in a05/09/1989Knuckle Boom Crane on a Constant LevelAbove the Ground5,328,040Thrust-Centering Crane and Method07/12/19945,487,478Inverted Kingpost Crane01/30/19965,669,517Articulating Boom Incorporating a Linkage09/23/1997Counterweight6,336,565Articulating Truss Boom01/08/20026,672,467Articulating Truss Boom01/06/2004